Problem: What do the following two equations represent? $-2x+4y = 5$ $6x-12y = -15$
Answer: Putting the first equation in $y = mx + b$ form gives: $-2x+4y = 5$ $4y = 2x+5$ $y = \dfrac{1}{2}x + \dfrac{5}{4}$ Putting the second equation in $y = mx + b$ form gives: $6x-12y = -15$ $-12y = -6x-15$ $y = \dfrac{1}{2}x + \dfrac{5}{4}$ The above equations turn into the same equation, so they represent equal lines.